THEORIES OF COMPLETE DENTURE IMPRESSIONS.pptx

in detail explanation on theories of complete denture

1. THEORIES OF COMPLETE DENTURE IMPRESSIONS Dr PRAVEEN B Professor Department of Prosthodontics and Implantology CODS, Davangere

2. INTRODUCTION Definition : Complete denture impression is the process of recording the entire denture-bearing area to ensure optimal fit, retention, stability, and support. Objective : To create a denture base that accurately adapts to the edentulous ridge and provides comfort and function. Key Theories : Various impression philosophies aim to distribute forces efficiently and enhance denture performance.

3. SELECTIVE PRESSURE THE ORY Proposed by : Boucher (1950) Principle : Some areas should bear more pressure while others remain stress-free. Impression Technique : Maximum pressure on primary stress-bearing areas (e.g., buccal shelf in the mandible, posterior palatal seal in the maxilla). Minimal pressure on secondary stress-bearing areas. Use of spacer wax to relieve pressure-sensitive regions. Advantages : Ensures even load distribution, better retention, and stability.

4. MUCOSTATIC THEORY Proposed by : Claude Lauritzen and Henry Page (1920s) Principle : Impression should record the tissues in their resting state, avoiding any distortion. Impression Material Used : Low-viscosity materials like zinc oxide eugenol or light-body elastomers. Advantages : Prevents soft tissue distortion, avoids tissue rebound. Disadvantages : May lead to poor retention due to lack of peripheral seal.

5. MUCOCOMPRESSIVE/FUNCTIONAL THEORY Proposed by : Carl O. Boucher (1940s) Principle: The impression is made under functional loading, simulating real-life conditions. Impression Material Used: High-viscosity materials like impression compound. Advantages : Ensures stability during function, better adaptation to forces during mastication. Disadvantages : Possible tissue displacement leading to long-term instability.

6. HYDROSTATIC THEORY (FLUID IMPRESSION THEORY) Proposed by : Charles E. Prange (1950s) Principle : A thin film of saliva between the denture and mucosa enhances retention through capillary attraction. Impression Technique : A uniform layer of fluid is maintained between the denture base and tissues. Advantages: Maximizes denture retention through the physical properties of fluids. Disadvantages : Difficult to achieve clinically; not widely used.

7. CONTEMPORARY APPROACHES Combination Technique : Merges mucostatic and mucocompressive principles for an optimal outcome. Uses selective pressure approach with border molding for better retention and stability. Digital Impressions : Advances in intraoral scanning technology for CAD/CAM dentures. Enhances accuracy and efficiency.

8. CONCLUSION No single impression technique is universally ideal. Choice depends on the patient’s oral conditions, ridge morphology, and clinician’s expertise. A combination of techniques is often required for the best outcome. Recent advancements like digital impressions are transforming denture fabrication.